Corns and calluses are common conditions of the feet that can be found in people of all ages, health, and activity levels. Essentially, corns and calluses are areas of skin that have become thickened due to pressure. This thickening is a natural defense mechanism of the skin. This mechanism is designed to respond to increased pressure from an external source, such as pressure seen from a shoe. When combined with an internal pressure source, like a prominent bone, the corn or callus will become even larger and possibly painful. Internal pressure sources can widely vary. In the toes, this is generally from toe contractures called hammertoes, in which the toe bones are contracted upward and the top of some of these bones becomes prominent on the top of the toe, or along the side where they will rub against the adjacent toe. In the foot, especially the ball of the foot, the internal pressure can come from prominence of the end of the long bones of the foot called the metatarals. These bones can be prominent due to either fat pad loss at the ball of the foot, or a downward position of the bones themselves. The way a person walks can also increase the pressure on the foot skin. As shoes or the ground exert pressure on the skin from the outside and the prominent bone exerts pressure from within, a reaction takes place in the skin's top layer. This reaction thickens the top layer and provides a natural defense for the skin from excessive pressure. This type of skin is called hyperkeratosis. Typically the word 'corn' describes a hyperkeratosis of the toes, and 'callus' describes a hyperkeratosis on the sides or bottom of the foot. Unfortunately, this natural defense can be a source of pain and discomfort as the skin thickens, and there is always a potential for skin to ulcerate underneath the corn or callus. When the pressure is too excessive, the tissue and skin underneath the hyperkeratosis begins to bruise, and eventually die. In most people, pain is felt during this long process. However, some people, diabetics in particular, have poor sensation in the feet and do not notice when this skin damage is occurring. This can lead to severe foot wounds if the hyperkeratosis is not periodically shaved down.



A variety of means may be used to treat corns and calluses. Treatment may be as simple as regular professional shaving of the tissue, combined with the use of skin softeners or moisturizers, padding for comfort and protection, as well as the use of wider, deeper, or more supportive shoes. We do not recommend people use razors, knives, or scissors to cut their own corns and calluses. It is far too easy to cut too deeply, as positioning oneself to do it properly is difficult. This especially goes for diabetics. Instead, we recommend the use of a pumice stone or emery board after bathing every few days to gently file the skin while it is softened from the water. For severely thick corns and calluses, diabetics, or those in pain, we recommend that a podiatrist take care of the hyperkeratosis, as it will be much safer and more effective. The use of medicated corn pads is not recommended, as they contain an acid which can easily burn the surrounding healthy skin when improperly applied. However, padding which is non medicated and provides a aperture to cradle the thick skin, or gel to pad over it will be acceptable. It is very important to reduce the friction and pressure on the skin, otherwise the corn or callus will continue to get larger. For calluses on the bottom of the foot, the use of prescription shoe inserts called orthotics can redistribute the pressure found when standing and walking, and this can lessen or even eliminate some callus formation. Although over-the-counter store bought inserts can be helpful, only orthotics made from a casting of the foot (not simply a tracing or foam box impression) will change the foot function enough to make a significant difference to the callus formation, as a complete foot exam and prescription based on the foot structure is needed.

The above measures may lessen the size or severity of the corn or callus, but due to continued pressure they will always return again. Sometimes, despite the best care at home, the corn or callus will cause continued pain and may even worsen. Permanent correction and relief of the hyperkeratosis requires surgery to address any underlying bone deformity, with either removal of the prominent bone causing internal pressure (with changing of shoes to relieve the external pressure) or correction of any contributing foot deformity (such as toe contractures or bunions) that also causes the internal pressure. Corns on the toes are easily resolved when the underlying toe contracture is repaired. With a straight toe, there is little chance that shoes will irritate the skin, unless the shoe is too tight to begin with. Equally, removal of prominent portions of bone in the toes as seen with hammertoes next to each other will relieve the pressure two adjacent toes exert on each other. There are numerous procedures for correcting calluses. These surgical procedures are generally very successful in relieving the painful callus, although these procedures can sometimes have an unintended result, in which the pressure point is simply shifted over to the next bone, resulting in a new callus. The procedures vary from bone cuts that lift the bone up, to shortening procedures and even partial bone removal in some severe cases.

Although corns and calluses are common problems, certain people can have significant issues associated with them, including pain and even wounds. Treatment generally is simple, but requires regular self-care to keep them under control. Medical and surgical care is available, and may be necessary in cases that are resistant to self-care.